Update code to mirror r1747461 of apr-2.0 apr_cstr.c.

More legible, slightly more performant.  Based on the
compiler in use and -O flags, YMWV.

git-svn-id: https://svn.apache.org/repos/asf/httpd/httpd/trunk@1747468 13f79535-47bb-0310-9956-ffa450edef68

diff --git a/server/util.c b/server/util.c
index f628d78a56b3d5d50d3f7a2a947f9e95712394e6..8820bfa9fb7dcd37b99405e5958800ccddd2c743 100644 (file)
--- a/server/util.c
+++ b/server/util.c
@@ -3228,11 +3228,12 @@ AP_DECLARE(int) ap_array_str_contains(const apr_array_header_t *array,
 
 #if !APR_CHARSET_EBCDIC
 /*
- * Provide our own known-fast implementation of str[n]casecmp()
- * NOTE: Only ASCII alpha characters 41-5A are folded to 61-7A,
- * other 8-bit latin alphabetics are never case-folded!
+ * Our own known-fast translation table for casecmp by character.
+ * Only ASCII alpha characters 41-5A are folded to 61-7A, other
+ * octets (such as extended latin alphabetics) are never case-folded.
+ * NOTE: Other than Alpha A-Z/a-z, each code point is unique!
  */
-static const unsigned char ucharmap[] = {
+static const short ucharmap[] = {
     0x0,  0x1,  0x2,  0x3,  0x4,  0x5,  0x6,  0x7,
     0x8,  0x9,  0xa,  0xb,  0xc,  0xd,  0xe,  0xf,
     0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
@@ -3266,79 +3267,87 @@ static const unsigned char ucharmap[] = {
     0xf0, 0xf1, 0xf2, 0xf3, 0xf4, 0xf5, 0xf6, 0xf7,
     0xf8, 0xf9, 0xfa, 0xfb, 0xfc, 0xfd, 0xfe, 0xff
 };
-
 #else /* APR_CHARSET_EBCDIC */
-/* Derived from apr-iconv/ccs/cp037.c for EBCDIC case comparison,
-   provides unique identity of every char value (strict ISO-646
-   conformance, arbitrary election of an ISO-8859-1 ordering, and
-   very arbitrary control code assignments into C1 to achieve
-   identity and a reversible mapping of code points),
-   then folding the equivalences of ASCII 41-5A into 61-7A, 
-   presenting comparison results in a somewhat ISO/IEC 10646
-   (ASCII-like) order, depending on the EBCDIC code page in use.
+/*
+ * Derived from apr-iconv/ccs/cp037.c for EBCDIC case comparison,
+ * provides unique identity of every char value (strict ISO-646
+ * conformance, arbitrary election of an ISO-8859-1 ordering, and
+ * very arbitrary control code assignments into C1 to achieve
+ * identity and a reversible mapping of code points),
+ * then folding the equivalences of ASCII 41-5A into 61-7A, 
+ * presenting comparison results in a somewhat ISO/IEC 10646
+ * (ASCII-like) order, depending on the EBCDIC code page in use.
+ *
+ * NOTE: Other than Alpha A-Z/a-z, each code point is unique!
  */
-static const unsigned char ucharmap[] = {
-       0x00, 0x01, 0x02, 0x03, 0x9C, 0x09, 0x86, 0x7F,
-       0x97, 0x8D, 0x8E, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
-       0x10, 0x11, 0x12, 0x13, 0x9D, 0x85, 0x08, 0x87,
-       0x18, 0x19, 0x92, 0x8F, 0x1C, 0x1D, 0x1E, 0x1F,
-       0x80, 0x81, 0x82, 0x83, 0x84, 0x0A, 0x17, 0x1B,
-       0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x05, 0x06, 0x07,
-       0x90, 0x91, 0x16, 0x93, 0x94, 0x95, 0x96, 0x04,
-       0x98, 0x99, 0x9A, 0x9B, 0x14, 0x15, 0x9E, 0x1A,
-       0x20, 0xA0, 0xE2, 0xE4, 0xE0, 0xE1, 0xE3, 0xE5,
-       0xE7, 0xF1, 0xA2, 0x2E, 0x3C, 0x28, 0x2B, 0x7C,
-       0x26, 0xE9, 0xEA, 0xEB, 0xE8, 0xED, 0xEE, 0xEF,
-       0xEC, 0xDF, 0x21, 0x24, 0x2A, 0x29, 0x3B, 0xAC,
-       0x2D, 0x2F, 0xC2, 0xC4, 0xC0, 0xC1, 0xC3, 0xC5,
-       0xC7, 0xD1, 0xA6, 0x2C, 0x25, 0x5F, 0x3E, 0x3F,
-       0xF8, 0xC9, 0xCA, 0xCB, 0xC8, 0xCD, 0xCE, 0xCF,
-       0xCC, 0x60, 0x3A, 0x23, 0x40, 0x27, 0x3D, 0x22,
-       0xD8, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
-       0x68, 0x69, 0xAB, 0xBB, 0xF0, 0xFD, 0xFE, 0xB1,
-       0xB0, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
-       0x71, 0x72, 0xAA, 0xBA, 0xE6, 0xB8, 0xC6, 0xA4,
-       0xB5, 0x7E, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
-       0x79, 0x7A, 0xA1, 0xBF, 0xD0, 0xDD, 0xDE, 0xAE,
-       0x5E, 0xA3, 0xA5, 0xB7, 0xA9, 0xA7, 0xB6, 0xBC,
-       0xBD, 0xBE, 0x5B, 0x5D, 0xAF, 0xA8, 0xB4, 0xD7,
-       0x7B, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
-       0x68, 0x69, 0xAD, 0xF4, 0xF6, 0xF2, 0xF3, 0xF5,
-       0x7D, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
-       0x71, 0x72, 0xB9, 0xFB, 0xFC, 0xF9, 0xFA, 0xFF,
-       0x5C, 0xF7, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
-       0x79, 0x7A, 0xB2, 0xD4, 0xD6, 0xD2, 0xD3, 0xD5,
-       0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
-       0x38, 0x39, 0xB3, 0xDB, 0xDC, 0xD9, 0xDA, 0x9F
+static const short ucharmap[] = {
+    0x00, 0x01, 0x02, 0x03, 0x9C, 0x09, 0x86, 0x7F,
+    0x97, 0x8D, 0x8E, 0x0B, 0x0C, 0x0D, 0x0E, 0x0F,
+    0x10, 0x11, 0x12, 0x13, 0x9D, 0x85, 0x08, 0x87,
+    0x18, 0x19, 0x92, 0x8F, 0x1C, 0x1D, 0x1E, 0x1F,
+    0x80, 0x81, 0x82, 0x83, 0x84, 0x0A, 0x17, 0x1B,
+    0x88, 0x89, 0x8A, 0x8B, 0x8C, 0x05, 0x06, 0x07,
+    0x90, 0x91, 0x16, 0x93, 0x94, 0x95, 0x96, 0x04,
+    0x98, 0x99, 0x9A, 0x9B, 0x14, 0x15, 0x9E, 0x1A,
+    0x20, 0xA0, 0xE2, 0xE4, 0xE0, 0xE1, 0xE3, 0xE5,
+    0xE7, 0xF1, 0xA2, 0x2E, 0x3C, 0x28, 0x2B, 0x7C,
+    0x26, 0xE9, 0xEA, 0xEB, 0xE8, 0xED, 0xEE, 0xEF,
+    0xEC, 0xDF, 0x21, 0x24, 0x2A, 0x29, 0x3B, 0xAC,
+    0x2D, 0x2F, 0xC2, 0xC4, 0xC0, 0xC1, 0xC3, 0xC5,
+    0xC7, 0xD1, 0xA6, 0x2C, 0x25, 0x5F, 0x3E, 0x3F,
+    0xF8, 0xC9, 0xCA, 0xCB, 0xC8, 0xCD, 0xCE, 0xCF,
+    0xCC, 0x60, 0x3A, 0x23, 0x40, 0x27, 0x3D, 0x22,
+    0xD8, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
+    0x68, 0x69, 0xAB, 0xBB, 0xF0, 0xFD, 0xFE, 0xB1,
+    0xB0, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
+    0x71, 0x72, 0xAA, 0xBA, 0xE6, 0xB8, 0xC6, 0xA4,
+    0xB5, 0x7E, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
+    0x79, 0x7A, 0xA1, 0xBF, 0xD0, 0xDD, 0xDE, 0xAE,
+    0x5E, 0xA3, 0xA5, 0xB7, 0xA9, 0xA7, 0xB6, 0xBC,
+    0xBD, 0xBE, 0x5B, 0x5D, 0xAF, 0xA8, 0xB4, 0xD7,
+    0x7B, 0x61, 0x62, 0x63, 0x64, 0x65, 0x66, 0x67,
+    0x68, 0x69, 0xAD, 0xF4, 0xF6, 0xF2, 0xF3, 0xF5,
+    0x7D, 0x6A, 0x6B, 0x6C, 0x6D, 0x6E, 0x6F, 0x70,
+    0x71, 0x72, 0xB9, 0xFB, 0xFC, 0xF9, 0xFA, 0xFF,
+    0x5C, 0xF7, 0x73, 0x74, 0x75, 0x76, 0x77, 0x78,
+    0x79, 0x7A, 0xB2, 0xD4, 0xD6, 0xD2, 0xD3, 0xD5,
+    0x30, 0x31, 0x32, 0x33, 0x34, 0x35, 0x36, 0x37,
+    0x38, 0x39, 0xB3, 0xDB, 0xDC, 0xD9, 0xDA, 0x9F
 };
 #endif
 
-AP_DECLARE(int) ap_casecmpstr(const char *s1, const char *s2)
+AP_DECLARE(int) ap_casecmpstrn(const char *s1, const char *s2)
 {
-    const unsigned char *ps1 = (const unsigned char *) s1;
-    const unsigned char *ps2 = (const unsigned char *) s2;
-
-    while (ucharmap[*ps1] == ucharmap[*ps2]) {
-        if (*ps1++ == '\0') {
-            return (0);
-        }
-        ps2++;
+    const unsigned char *str1 = (const unsigned char *)s1;
+    const unsigned char *str2 = (const unsigned char *)s2;
+    for (;;)
+    {
+        const int c1 = (int)(*str1);
+        const int c2 = (int)(*str2);
+        const int cmp = ucharmap[c1] - ucharmap[c2];
+        /* Not necessary to test for !c2, this is caught by cmp */
+        if (cmp || !c1)
+            return cmp;
+        str1++;
+        str2++;
     }
-    return (ucharmap[*ps1] - ucharmap[*ps2]);
 }
 
 AP_DECLARE(int) ap_casecmpstrn(const char *s1, const char *s2, apr_size_t n)
 {
-    const unsigned char *ps1 = (const unsigned char *) s1;
-    const unsigned char *ps2 = (const unsigned char *) s2;
-    while (n--) {
-        if (ucharmap[*ps1] != ucharmap[*ps2]) {
-            return (ucharmap[*ps1] - ucharmap[*ps2]);
-        }
-        if (*ps1++ == '\0') {
-            break;
-        }
-        ps2++;
+    const unsigned char *str1 = (const unsigned char *)s1;
+    const unsigned char *str2 = (const unsigned char *)s2;
+    while (n--)
+    {
+        const int c1 = (int)(*str1);
+        const int c2 = (int)(*str2);
+        const int cmp = ucharmap[c1] - ucharmap[c2];
+        /* Not necessary to test for !c2, this is caught by cmp */
+        if (cmp || !c1)
+            return cmp;
+        str1++;
+        str2++;
     }
-    return (0);
+    return 0;
 }
+